Field of the Invention
The present invention relates to an electrochemical device having an electric storage element constituted by a positive electrode, a negative electrode, and separators, being wound together.
Description of the Related Art
Lithium ion capacitors, electric double-layer capacitors, lithium ion secondary batteries, and other electrochemical devices are constituted in such a way that an electric storage element, constituted by a positive electrode and a negative electrode stacked together with a separator in between, is immersed in electrolytic solution. Wound-type electrochemical devices formed by winding together a positive electrode, a negative electrode, and separators, are also widely used.
Joined to the positive electrode and negative electrode, respectively, are electrode terminals used for electrical connection with the outside. For example, Patent Literature 1 describes an electric double-layer capacitor whose structure is such that a positive electrode and a negative electrode, each of which, having a flat electrode tab crimped to it, are wound together. Also, Patent Literature 2 describes an electric double-layer capacitor whose structure is such that the lead tab joined to the negative electrode is led out to the negative-electrode external terminal side and the opposite side of the negative-electrode terminal side.